1. Field of the Invention
The present invention relates to a disc cartridge. More particularly, the present invention relates to a disc cartridge in which an optical disc is rotatable within in a cartridge main body.
2. Background of the Invention
In general, a disc cartridge has a cartridge main body and a shutter member. The cartridge main body is formed by abutting and interconnecting first and second halves. Information signals recorded on an optical disc rotatable within the cartridge main body of the disc cartridge may be read using an optical head provided within a reproducing apparatus. To this end, the disc cartridge containing the optical disc therein has a signal readout exposing the optical disc to the optical head.
With such a disc cartridge, should the aperture be left open, the optical disc contained within the cartridge main body remains partially exposed to outside. Consequently, it is not possible to prevent deposition of dust and dirt on the optical disc with could result in damage to the optical disc.
Thus, a disc cartridge with a signal readout aperture is provided with a shutter member for closing the aperture when the disc cartridge is not loaded on the reproducing apparatus, such as during storage. The shutter member is supported for movement along the outer lateral side of the cartridge main body. The shutter member is formed by bending a metallic plate of a reduced thickness by a metallic mold. The shutter member includes a plate section for closing the aperture in the disc cartridge and a web section which acts as a slide guide. The web section is provided at the proximal side of the plate section and has an engaging part engaged with a groove formed in a lateral side of the cartridge main body.
The plate section is rectangularly-shaped and is of a size sufficient to close the aperture and is movable along the outer lateral surface of the half of the cartridge having the aperture. The web section extends along the lateral side of the cartridge main body and has an engaging part engaged to the groove formed in the lateral side of the cartridge main body.
A disc cartridge with a shutter member associated with only one of the cartridge halves, such the disc cartridge as described in, for example, JP Patent KOKAI Publication No. 61-255570 (1986), has been proposed. With this disc cartridge, the plate section is provided to a pawl engaged with a groove formed in the outer lateral side of the cartridge main body for preventing the shutter member from becoming detached from the plate section. The pawl is provided obliquely at a certain predetermined angle with respect to the plate section for assuring reliable prevention of detachment of the shutter member from the cartridge main body.
However, with a pawl formed obliquely with in respect to the plate section, the metallic mold used for fabricating the shutter member becomes complex to manufacture. Above all, should burrs be produced at the distal end of the pawl, the cartridge halves tend to be scraped by these burrs during movement of the shutter member.
It is an object of the present invention to provide a disc cartridge which resolves the above-mentioned problems.
It is another object of the present invention to provide a disc cartridge to which a shutter member is reliably attached.
According to the present invention, there is provided a disc cartridge including a first half, a second half, and a shutter member. The second half is connected to the first half. The second half is formed with a first aperture facing an optical head and a second aperture via which a rotational disc driving device is introduced. The shutter member is slidably mounted on the second half and has a first plate portion, at least one second plate portion and a connecting portion. The first plate portion opens or closes the first aperture and is in contact with the outer surface of the second half. At least one second plate portion extends parallel to the first plate portion and is engaged with the inner surface of the second half. The connecting portion interconnects the first and second plate portions to complete the cross-sectional shape of a letter U of the shutter member. The length of the second plate portion is less than the length of the first plate portion.
According to the present invention, the shutter member may be reliably mounted on the cartridge main body to realize its stable movement.